One of the biggest uncertainties for Honolulu’s commuter rail project — aside from concerns that there’s not enough money to build it — is how much it will cost to relocate utilities along the proposed route.

On Tuesday, HART’s Project Management Oversight Committee discussed the complexities of moving water, sewer and power lines to make way for construction of the rail line on Dillingham Boulevard and through the city center.

It was part of a special meeting held at 5:30 p.m. at the Mission Memorial Auditorium in downtown Honolulu as a way to encourage more public participation. Typically HART meetings are held on weekday mornings while many people are work.

But Tuesday’s meeting did little to provide more clarity on the true costs of utility relocation. It’s a costly proposition, and one that HART officials admitted they don’t have a handle on.

As of October, HART estimated that the act of moving power, water and sewer lines would cost at least $120 million more than expected. But now even that figure is up in the air, especially after it was revealed that the project costs could be as high as $8.1 billion.

If that $8.1 billion estimate is correct, HART wouldn’t have enough money to build the full 20-mile system that is supposed to run from East Kapolei to Ala Moana Center.

The project oversight committee didn’t address the shortage of funds Tuesday. Instead, board members are waiting for a June 8 meeting to look at options to possibly shorten the route or alter the project to fit its budget.

As HART Chairwoman Colleen Hanabusa said, “It’s all a matter of how far can we get with the money we have.”